The present invention relates to jet aircraft engines, in particular to a thrust reverser mechanism for a jet aircraft engine.
A jet engine thrust reverser operates to redirect either engine exhaust gases or engine fan air in a lateral and forward direction. Thrust reverser operation is typically initiated by the pilot of the aircraft once the aircraft has touched down on the runway. The exhaust gases or engine fan air redirected by the thrust reverser cause a rearward net thrust of the aircraft engine to aid in slowing an airplane during landing rollout. In a typical high bypass jet engine, redirection of the air is accomplished by a plurality of blocker doors and reversing vanes operating in conjunction with a moveable transcowl. The blocker doors move into the stream of bypass air to redirect the air through the reversing vanes, which are simultaneously uncovered by the moveable transcowl to permit the redirected air to escape in a lateral and forward direction around the periphery of the engine nacelle.
Multiple redundant locks are typically employed to prevent an inadvertent deployment of the thrust reverser transcowl. The primary locks typically comprise mechanical locks on the actuators that move the transcowl. Pressure to the actuators cause the primary locks to be released to permit the transcowl to move. Secondary and tertiary thrust reverser locks typically comprise hydraulic, pnuematic or electrically actuated locks acting on the actuators, the actuator synchronization shaft, or directly on the moveable transcowl. A prior art thrust reverser lock that mechanically locks the transcowl to the engine nacelle is disclosed in U.S. Pat. No. 5,404,714 to Davies. The prior art lock comprises a rotatable jaw that engages a locking pin of the moveable thrust reversing member. The rotatable jaw is locked in position by a removable slide that wedges between the rotatable jaw and an anvil to prevent rotation of the jaw. When the prior art lock prevents an inadvertent deployment of the thrust reverser, the slide must bear the entire force of the thrust reverser locking pin. Accordingly, the slide must be of robust construction, with commensurate weight and cost.